Knowledge Of Waterproof And Moisture Permeable Fabrics

Type: high density fabric is made of high count microfiber and other superfine synthetic fibers, which makes the fabric have high water vapor penetrability and water repellency after water repellent finishing.

The fabric made of separated fiber is supported by high shrinkage, and its density is 20 times higher than that of ordinary fabric. Its water resistance is up to 600mm water column and its moisture permeability is 7000g/m 2.24h.

Types of waterproof and moisture permeable fabrics:

High density fabric

The high count microfiber and other ultra-fine synthetic fibers are used to make the fabric tightly, so that the fabric has higher water vapor penetrability and water repellency after water repellent finishing.

The fabric made of separated fiber is supported by high shrinkage, and its density is 20 times higher than that of ordinary fabric. Its water resistance is up to 600mm water column and its moisture permeability is 7000g/m 2.24h.

According to the waterproofing mechanism of lotus leaf, the water resistant and waterproof fabric made of superfine fiber is made by Japanese Japanese company. Its water resistance is 700mm water column and its moisture permeability is greater than 8000g/m 2.24h.

High density is characterized by good moisture permeability, good softness and draping, but low water resistance (generally less than 100mm). Moreover, it has many broken ends, high defective products, difficult dyeing and finishing, and low tear resistance and wear resistance of fabrics.

Coated fabric

The coating fabric can be divided into two types: hydrophilic coating and microporous coating. The hydrophilic coating fabric is coated with a hydrophilic coating on the surface of the fabric, and the coating can be waterproof because the coating covers all the gaps of the fabric.

If there are hydrophilic groups on the polymer chain and the content and arrangement are suitable, they can interact with water molecules. With the help of hydrogen chains and other intermolecular forces, water molecules can be adsorbed on the high temperature side, and can be desorbed through the hydrophilic group on the polymer chain to the low humidity side.

Moisture permeation is a process of "adsorption diffusion desorption".

The hydrophilic group is called "chemical step stone".

At the same level, the size of intermolecular pores and chain segments is selective for water molecules of different diameters, which is equivalent to "molecular sieve".

The introduction of hydrophilic groups will improve its moisture permeability.

The coating fabric is simple in processing, characterized by low moisture permeability and low water resistance.

Because of the limitations of raw materials, technology and the method itself, it has not been able to solve the contradiction between moisture permeability, air permeability and water resistance and washability.

Composite fabric

The composite fabric integrates excellent waterproof, moisture permeability and wind protection and warmth retention, and has obvious technical advantages.

It uses composite technology to combine ordinary textile fabrics with the excellent properties of high-tech film products. It complementarity and full expression of the characteristics of the times of traveling and changing functions. It represents the highest level of waterproof and moisture permeable fabrics at present.

At present, there are mainly TPU thin films, PES films and e-PTFE thin films.

In terms of structure, TPU and PES films are microporous. They pass through the sweat of clothing effectively through the hydrophilicity of structural polymers.

Polymer molecules can form weak crosslinks with water molecules and pport water along their own polymer chains. Their direction is affected by temperature and humidity. As long as the temperature and humidity inside the clothing are higher than the outside, the direction of pferring water vapor molecules is from inside to outside.

The e-PTFE thin film is microporous. It uses unique processing technology to make the film form a porous structure with a film thickness of about 25 m to 35 m. The opening rate is as high as 80 m, and about 1000000000 micropores per square centimeter. The pore size is 700 times larger than that of the water vapor molecule. The sweat gas can pass through, and the pore size is about 5000 to 20000 times smaller than the water droplet. Liquid water can not pass through.